42042 straight triangle 4-5-6

[skaah]

Hi all, I was building 42042 and I noticed these straight triangles:

Two sides at 90 degrees: 4 and 5 studs. 

And an angled beam of 6 studs connecting.

It matches up perfectly, the elements are not under stress.

However, I don't understand how this can exist. Pythagoras theorem a^2+b^2 = c^2 doesn't work out: 16 + 25 != 36.

Is there anyone who understands the maths better than me who can enlighten me why this works in the LEGO system?

I tried the 3-4-5 triangle but it doesn't match up! Do I have to subtract 1 of each beam length for some reason?

[suffocation]

The length is actually from mid-first hole to mid-last hole, so always add 1 to your Pythagorean triangles to get Lego equivalents.

[Mechbuilds]

We need a lego pythagoras theorem calculator for triangles.. @Sariel help our lazy arses! 

Edited September 16, 2020 by Mechbuilds

[aeh5040]

There have been some prior discussions of similar issues:

 

[ginger-snapped]

You should check out http://tkelcreations.blogspot.com/p/blog-page_24.html. It shows the perfect (or close to perfect) lego right triangles in terms of length of beams which makes it nice to work with for lego since there is no adding/subtracting 1. And it's not just the ones with all whole numbers, some are for lengths that go down to a half stud.